Introduction: The experiment is based upon the idea that heart and breathing rate changes after exercise to a certain extent in different ages. During exercise an individual needs to obtain sufficient oxygen to meet his/her energy needs. Extra oxygen can be provided by increased breathing and heart rate The experiment is tested on different boys of different ages assumingly with the same built and height. There are many factors that affect heart rate which includes exposure to heat, stress, drugs (some), emotions, infections and fevers, caffeine intake and age. This research examines the effect of exercise on an individual’s heart and breathing rate.
Hypothesis: Boys heart and breathing rate during exercise goes down with age.
Independent variable: Age
Dependent variable: breathing rate and heart rate
Controlled variable: duration of exercise, type of exercise, gender(boys), height and weight
Measured the participants’ heart rate per minute by using two fingers on their wrist or neck. The candidate had to count their breathing rate per minute. Every exhale and inhale was considered one.
The candidate then took to the stairs where the subject ran at his own pace. Each candidate ran for 1 minute (60 seconds) under a stopwatch or phone.
Once the participant had run 1 minute, the pulse and breathing rate it taken quickly for one minute. Again the candidate measures their own breathing rate as the heart rate is taken for him by the wrist or the neck (depending on where we found a good beat)
The candidate then took the exercise once again later in the day to ensure accuracy/reliability. ( repeat in method)
The first table (under) is the breathing rate of each participant prior to and following the exercise:
Investigation of breathing rate.
Initial Breathing rate
Breathing rate After 1 minute of exercise
Increase in breathing rate per minute
Mean increase in breathing rate per minute.
Discussion of results:
The results show that the heart rate during exercise decreases with age from 11years- 14 years whereas the heart rate of the 15 and 16 year old increases. Heart rates achieved during exercise are expected to decrease with age. These results are therefore consistent with what was expected between 11 and 14 years however, the heart rates of the 15 and 16 year old do not agree with what was expected. Perhaps the 15 and 16 year old were not as fit as expected.
The results show a more or less uniform increase in breathing rate for the boys aged 11 – 14. The 15 year old and 16 year old had a much greater increase in breathing rate during exercise. It is expected that younger people breathe faster because they need to provide their body with plenty of oxygen and their lungs have a lower capacity. Older children don’t need to breathe that fast because their lungs are larger and can hold more oxygen per breath. The results do not agree with this. The 11 – 14 year old have an almost uniform increase in breathing rate during exercise. This could be explained by the fact that these boys had almost the same size and build therefore the same size of lungs. However, the 15 and 16 year old boys needed to breathe much faster during exercise. The reason for their high breathing rate could be the lack of fitness. Remember that these are the boys with the higher heart rate.
In conclusion, we could say that heart rate during exercise decreases with age. There appeared to be little difference in breathing rate during exercise with the age of the boys. We are treating the results of the 15 and 16 year old as anomalous.
During the investigation I observed colleagues also working on the investigation lacking precision in watching the stopwatch/phone carefully and there were incidents were some candidates ran slightly more by five seconds. There were other incidents to which another colleague would forget the number of pulses and would either round or start over. Also there were several incidents were the candidates would lie about the number counted for the breathing rather because they were unsure how to. To trust the candidates to count how many breaths in a minute seemed to be a difficult issue whereby the candidate would force to exhale and inhale air instinctively for concentrating on their breathing, therefore giving incorrect data. Candidates also ran at their own pace therefore some candidates did more work than others. At some stage the stairs were wet and the assumption is that some of the candidates ran slower to prevent an accident. An attempt to find candidates that had the sane build and size seemed to be difficult as an 11 year old would not have the same build or size as a 16 year old.
The experimenters should take both the heart rate and breathing rate to minimise on errors caused by participants.
Height and weight could be measured so that candidates are of equal height and weight.
Using the same stopwatch to avoid errors of difference in the phone and stopwatch.